<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>旧版本网页布局</title>
  <style>
    body {
      margin: 20px;
      padding: 0;
      background-color: #eee;
    }
    .wrapper {
      width: 90%;
      margin: 40px auto;
    }
    .left-panel{
      width: 25%;
      float: left;
      background-color: #fff;
    }
    .right-panel{
      width: 70%;
      float: right;
      background-color: #fff;
    }
    @media screen and (min-width: 900px) {
      .wrapper {
        background-color: orange;
      }
    }
  </style>
</head>
<body>
  <div class="wrapper">
    <div class="left-panel">
      <p>Lorem ipsum dolor sit amet consectetur adipisicing elit. Veritatis tenetur eum eos numquam vero, in modi iusto consectetur officia optio?</p>
    </div>
    <div class="right-panel">
      <p>Lorem ipsum dolor sit, amet consectetur adipisicing elit. Rerum rem incidunt commodi veniam possimus accusamus nesciunt autem, molestiae odit placeat explicabo minima consequuntur porro aliquid error, quae dignissimos quos vel.</p>
      <p>Lorem, ipsum dolor sit amet consectetur adipisicing elit. Architecto aspernatur maiores velit aperiam sunt consectetur pariatur omnis rerum, odit fugit!</p>
    </div>
  </div>
</body>
</html>